William's Moon Patrol power supply heat sink

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I'm restoring a William's Moon Patrol for a friend I decided to buy a used power supply board and heat sink off of ebay. The originals had terrible burn marks on the power connectors and a technician had run jumper wires to bypass the damage. Also, the power board had corrosion around the pins for the ICs.

The power supply board and heat sink from ebay looked much better and the connectors were very clean, so I went ahead did a recap on the power board, but I left the heat sink as-is.

Now, when I hooked everything up, the game came up and you could play it but there was no sound. LEDs #2 and #3 were lit but #1 was off. Soon after, the power supply board blew fuse #5.

My first question is about the heat sinks. The heat sinks look identical in every way, but the bottle-cap transistors have different numbers and I'm wondering if this is part of the problem.

Transistors in original Moon Patrol heat sink:

8127
2N6057

8252
2N3055

Transistors in heat sink from ebay:

5162-09
425-00
8226

9552-00
8226

If anyone has insight into this, that would be awesome.
 
Moon Patrol you could just use a switching power supply. it's not a real Williams game.
 
Transistors in original Moon Patrol heat sink:

8127
2N6057

8252
2N3055
The transistors in your original match the schematic. You can get replacements here:
2N6059 replaces the 2N6057

The 2N3055 does your +12, and if LED2 was lit, it's likely OK, but check test point 3 with multimeter for +12V.
The 2N6057 handles the +5, which is LED1.
 
Williams had them marked with their own Part Numbers.

The 5162 (5162-09425 is the 2N6057 for the +5v. (Can use 2N6059).
The 8246 is the date code: 46th week of 1982

The 9552 (Q1) is the 2N3055 for the regulated +12v.

Cool they both were made in the same week of 1982!

The 2N6057 (Q2) +5v Darlington Power Transistor goes closest to where the wiring exits the heatsink.

A few comments:
  • Only replace when bad
  • Use a Silicone Insulator (TO-3 Package) in lieu of Mica - Don't use any heatsink compound
  • Beware of Counterfeits! Tons of fake ones out there (especially the 3055's) - Try and buy NOS ones.
Hope this helps!
~Brad
 
it's not a real Williams game.
It's ok Moon Patrol, you're every bit as good as those other Williams games. When they hum theme music, who's music is it? That's right, Moon Patrol, it's your music. Who makes you excited about reaching different parts of the alphabet? That's right, you do, Moon Patrol. Now get back out there and be proud of who you are.
 
Thanks everyone for the feedback. I am strongly considering going with a modern switching power supply for my friend's Moon Patrol. I would hate to deliver it to his house and have the linear power supply burn up 3 months later. Based on my research, It seems that this is a popular option for certain William's games like Moon Patrol.

I was thinking about going with this one that I found on eBay. Any opinions on it or suggestions for better options?

WILLIAMS POWER SUPPLY UPGRADE PCB / CONVERSION ( JOUST ROBOTRON SINISTAR ETC)

In the mean time, I might desolder the good connector of the new heat sink and move it over to the cabinet's original heat sink to see if it works or not.
 
Williams had them marked with their own Part Numbers.

The 5162 (5162-09425 is the 2N6057 for the +5v. (Can use 2N6059).
The 8246 is the date code: 46th week of 1982

The 9552 (Q1) is the 2N3055 for the regulated +12v.

Cool they both were made in the same week of 1982!

The 2N6057 (Q2) +5v Darlington Power Transistor goes closest to where the wiring exits the heatsink.

A few comments:
  • Only replace when bad
  • Use a Silicone Insulator (TO-3 Package) in lieu of Mica - Don't use any heatsink compound
  • Beware of Counterfeits! Tons of fake ones out there (especially the 3055's) - Try and buy NOS ones.
Hope this helps!
~Brad
So, basically, the heat sink off eBay should be safe to use even though the part numbers are different... assuming it works as expected.
 
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